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Abstract:

The P300 in Obsessive-Compulsive Disorder: A Meta-Analysis The P300 event-related potential (ERP) component has potential utility as a neurological marker of Obsessive Compulsive Disorder (OCD). Currently there is no reliable consensus relating to the direction and magnitude of P300 waveform differences between OCD and healthy control samples. We sought to combine previous research which documented P300 amplitude and latency data within OCD and healthy control groups using the Auditory Oddball (AO) task. A systematic search was conducted for studies reporting P300 amplitude and latency data of target trials in the AO task in patient (OCD) and control groups. Pooled effect sizes were calculated. Individuals with OCD demonstrated significantly reduced P300 latencies during target trials compared to healthy controls. Differences in the magnitude of P300 amplitude between individuals with OCD and healthy controls were non-significant. Attentional Bias in Individuals with Obsessive-Compulsive Disorder: An Eye-Tracking Methodology Attentional biases are implicated in theoretical models of Obsessive-Compulsive Disorder, however they are not consistently detected using conventional reaction time paradigms. Eye-tracking methods enable greater precision in revealing patterns of attentional bias. Participants with OCD (n=16) were compared with a healthy control sample (n=16). Measures of vigilance, disengagement and maintenance bias were investigated by recording eye-movements during a free-gaze task in which pairs of neutral- and OCD, or neutral- and aversive images were presented. The OCD group demonstrated no evidence of vigilance or delayed disengagement biases. However there were significant group differences in measures of maintenance attentional bias. Evidence of hypervigilant orienting to all stimuli was observed during early visual processing.